Javascript /typeScript Interview Questions

1. Asynchronous JavaScript:

• Promises: Understand how to handle asynchronous operations gracefully. Async/Await: Learn this modern approach to asynchronous code which makes your asynchronous code look more like traditional synchronous code. Callbacks: Fundamental for asynchronous programming, though less preferred now due to "callback hell".

2. Functional Programming Concepts:

• First-Class Functions: Understanding that functions can be assigned to variables, passed as arguments, and returned from other functions. Higher-Order Functions: Functions that take other functions as arguments or return functions. Pure Functions, Side Effects, and State Mutation: Concepts essential for writing clean, maintainable, and predictable code. Closures: Understanding how an inner function has access to the outer function’s variables and the implications of this.

3. Advanced Techniques and Concepts:
   • Currying and Partial Application: Techniques for working with functions and improving code reusability. Memoization: Optimization technique to speed up function execution by storing results of expensive function calls. Prototypal Inheritance: Understanding the prototype chain, and how objects inherit properties and methods. Design Patterns: Learning patterns like Module, Singleton, Observer, Factory, etc., for solving common design problems.
4. Error Handling and Debugging:
   • Exception handling with try...catch.
   • Understanding and using JavaScript's debugging tools.
5. Advanced DOM Manipulation:

• Event Bubbling and Capturing: Understanding how events propagate through the DOM.
• Document Fragments and performance considerations when interacting with the DOM.
• Custom Events: Creating and dispatching custom event types.

6. ES6 and Beyond Features:

• Understanding the latest ECMAScript features such as arrow functions, template literals, spread/rest operators, destructuring, ES6 modules, and more.

7. Browser APIs and Web Technologies:

• WebSockets for real-time communication. Service Workers for offline capabilities and background tasks. WebRTC for peer-to-peer communication.